The invention relates to a mounting method for a semiconductor component.
Mounting methods for semiconductor components, in particular power semiconductor components, are known. In this case, a material stack, comprising the semiconductor component, solder material applied thereto, and contact/mounting elements applied on the solder material, is usually heated in its entirety to relatively high temperatures (up to 450° C.) in order to produce a soldering connection between the semiconductor component and the contact/mounting elements. Such a mounting method is illustrated in FIG. 1 and will briefly explained below.
In a first process step PS1, a contact/mounting element 1 (referred to hereinafter as “mounting element”), for example, a “leadframe” is heated to a temperature of approximately 400° C. and the surface thereof is cleaned by means of a gas treatment. The mounting element 1 is composed of copper, for example, and can serve as a cooling element. In a second process step PS2, the mounting element 1 is cooled to a temperature of approximately 380° C., and solder material 2 is applied to the surface of the mounting element 1 from a container 4. The applied solder material 2 is distributed on the surface of the mounting element 1 automatically in a third process step PS3, a semiconductor component 3 being applied to the solder material 2 in a fourth process step PS4 (for example by means of a corresponding pressing method by means of a pressing device 5). In a fifth process step PS5, a connection complex comprising mounting element 1, solder material 2 and semiconductor component 3 is cooled to approximately 200° C. (for example by water cooling or air cooling), whereby the hitherto liquid solder material 2 solidifies. This results in a “fixed”, hardened soldering connection between the mounting element 1 and the semiconductor component 3.
The method described in FIG. 1 has the disadvantage that an oxidation of the mounting element 1 takes place on account of the heating of the entire material stack (mounting element 1, solder material 2 and semiconductor chip 3). This may result in problems insofar as the reliability of the adhesion of the semiconductor component 3 on the mounting element 1 is concerned. Additional process steps are necessary in order to avoid this disadvantage.